The present invention pertains to cranes and, more particularly, to cranes used in the manipulation of equipment submerged in the water of a boiling water nuclear reactor (BWR).
Movement of equipment and components of a boiling water reactor is accomplished by the use of a heavy-duty overhead crane which comprises a part of the reactor system. Due to the limited space available within the pressure vessel and the geometry of the pool within which the loads are located, it may sometimes be necessary to lower the crane hook below the water surface. Because the water is radioactive, it is undesirable to wet the crane hook, hook block or cables therein, as they must then be thoroughly washed or otherwise decontaminated before they may be used again.
It is, therefore, a primary object of the present invention to provide a watertight cover for a crane hook, hook block, and cables which does not interfere with the crane operation.
The foregoing and other objects and advantages are achieved by a hook cover comprising a cylindrical rod interposed between the hook and the load. A circular seal, sliding carried on the rod, engages an imperforate cover member telescoped over the rod and the hook. Means are provided for drawing the seal and cover member toward the hook as the hook is lowered into the water.